- if (len < sizeof(struct ofp_header)) {
- ds_put_cstr(&string, "OpenFlow packet too short:\n");
+ if (!len) {
+ ds_put_cstr(&string, "OpenFlow message is empty\n");
+ } else if (len < sizeof(struct ofp_header)) {
+ ds_put_format(&string, "OpenFlow packet too short (only %zu bytes):\n",
+ len);